Utilization of chloracetic acid waste liquor



Patented July 28, 1925.

outrun stares PATENT OFFICE- WILLIAM S. OALCOTT, O13 PENNSGROVE. NEW' JERSEY, ASSIGNOR TO E. I. DU lONT DE NEMOURS 6c COMPANY, OF "WILMINGTON, DELAWARE, A CORPORATION OF DELA- WARE.

UTILIZATION OF CHLORACETIC ACID WASTE LIQUOR.

No Drawing. Application filed April 6, 1921, Serial No. 459,096. Renewed December 18, 1924.

To 027 whom it may concern.

.lle it known that .l'. llinnuiu; S. Gimme, a citizen ot the linitcd States, and a resident of lcnnsgrorc, in the county of Salem and State of New Jersey. have invented a certain new and useful Utilization of Chloraurctic Acid \Vaste Liquor, of which the following is a specification.

This invention relates to a process of treating a mixture containing monochlorand dichlor-acetic acids, such as the waste liquor for monochloracetic acid nianui'actane. to

form a valuable product.

In the manufacture of. chloracetic acid there is obtained a considerable quantity of a Waste mother liquor consisting of a mixture of monochlorand dichlor-aeetic acids substantially free from water. 1 v,lhave discoyered that by treatment with ii mctal such as iron this mixture 0* chlorinated acids can be reducedto acetic acid. The acetic acid combines with the iron used in the reduction, but can readily be liberated from this combination by treatment with a stronger mine "al acid such as sulphuric acid; by dis tillation the free acetic acid can be obtained in a pure state satisfactory for use either in the manufacture of chloracetic acid or for other purposes.

A typical waste liquor "from chloracctic acid manufacture has the following com-- position:

Parts.

Monochloracetic acid s-s 47.5 Dichloracetic acid 27.5 Acet-icacid 5.0

and also small amounts of. impurities such as sulphur chloride, hydrochloric acid, and sulphuric acid. A

My invention may be illustrated by the 'h lowing eXa1111.)le:-1O() pounds of the waste liquor ot' the composition given above are mixed with eighty pounds oi iron in the form of iron filings or crushed iron. The mass is then heated under a reflux condenser to 100 C. until the reaction is complete which requires approximately two hours. Hydrochloric acid gas is evolved duringthe treatment. Eighty-live pounds of (36 Bunnie sulphuric acid are then added, the mixture stirred, and the acetic acid distilled. off and condensed.- From. 100 pounds of the waste liquor there should be'obtained from 70 to 75 pounds of anhydrous acetic acid.

The proce s may be applied to any 1nixture of mono-chloracctic and dichloracetic acids, either with or without the presence of acetic acid. The exact (GIUPQIfllLLllOlS of little importance except that too high a temperature causes excessive loss of acetic acid, while too low a temperature lengthens the time of reduction. Instead of iron, zinc, tin, or other metals soluble in acid with the evolution of hydrogen may be used.

Although I have described my invention in detail Various changes may be made in the process as specifically disclosed without departing from the spirit and scope of the invention.

I claim 1. The process of producing glacial acetic acid which comprises bringing a mixture containing monechlorand dischlor-acetic acids and being substantially. free .from water into contact with a metal which is soluble in acid with evolution of hydrogen.

2. The process of, producing glacial acetic acid which comprises bringing a mixture containing monochl0rand dichlor-acetic acids and being substantially free from water into contact With a metal which is soluble in acid with evolution of hydrogen, adding to the resulting mixture an acid stronger than acetic acid, and removing the tree acetic acid which is formed.

3. The process of producing glacial acetic acid which comprises bringing a mixture containing monochlorand dichl0r-acetic acids, and being substantially free from water into contact with a metal which is soluble in acid with evolution of hydrogen,

adding concentrated sulphuric-acid to the resulting mixture, and ren'ioving therefrom the free acetic acid which is formed.

4. The process of producingglacial acetic acid which comprises bringing comminuted metallic iron into contact with a mixture containing monochlorand. dichlor-acetic acids and being substantiai'ly, free from ater. I r

5. The process of producing glacial acetic acid which comprises bringing coniminuted metallic iron. into contact with a mixture containing inonochlorand dichlor-aceti acids and being substantially free iron to the resul therefrom the so it tine;- mixture, and removing rec acetic acid which is qrn ed';

6. The process of producing glacial acetic sci-d which comprises bringing comminuted metallic iron into contest with a substantially anhydrous minturecontniniug monochlormixture containing iron acetate, adding conthe ecctic acid which is formed.

7. The process of producing glacial acetic acid which comprises bringing comminuted metallic iron into contact with a substantiuliy anhydrous mixture containing about dichlorecetic acid, and ahout 5 parts sold, adding concentrated sulphuric acid thereto to convert she iron acetate which is formed into iron sulphate and free acetic acid, and removing the latter. j The recess which comprises mixing SOparts o oomininuted iron with a solution containing about 427 parts of monochloracetic scid, about 47 parts of dichlorecetic ports of of ucetic ports or monochlorecetic acid, about 47 the mass under a refl ux condenser until mg re notion of the chloracetic acids is com;

adding about 85 parts of 66 sulphuric acid, and distilling oil the free acetic acid 9. 1c

10. The

which has been formed.

evolution of hydrogen.

process of producing acetic acid iquidcontaining and being subnto contact with acid with evolumixture and removing therefrom the free acetic. acid which is formed.

producing glacial which comprises bringing ,com-

liquid mixture containin acid and Water.

I Iii tiistimo ture.

acid, end slcouu'm 5 parts of acetic acid, heat- 1 a. chlor-acetic being substantially free from y whereof I aliix my signa- WILLIAM s. CALCOTT. 

